Method Statement: Installation of two-layer roll roofing from bitumen-polymer materials using a flameless method

Roll bitumen-polymer membranes on a fiberglass or polyester base are used as the primary waterproofing material. For the upper layer of the roofing carpet, a material with a surface density of 4.2...4.8 kg/m² and a tensile breaking force of at least 490 N (based on fiberglass cloth) or 590 N (based on polyester fabric) is used. A membrane with a density of 3.4...3.8 kg/m² is used for the lower layer. The surface density of the bitumen-polymer binder on the weldable side must be strictly at least 2.0±0.3 kg/m².

The flameless installation method involves gluing the roll carpet by dissolving the lower layer of the binder. For this purpose, a primer consisting of construction bitumen grade 70/30, diluted with kerosene or white spirit in a strict 1:3 ratio by weight, is used. This technology allows work to be carried out in both summer and winter periods on rigid bases (reinforced concrete slabs, cement-sand, or asphalt screeds).

Works are carried out in a single shift by a qualified team of roofers. When working in winter conditions or at freezing temperatures, roll materials must be pre-conditioned in a warm room. The use of the flameless method eliminates the use of an open flame, which is critically important at facilities with increased fire safety requirements.

1Rolled roofing material (e.g., ruberoid or similar bituminous membrane), being unrolled and applied to form the main waterproof carpet.

2Direction of work progression or material application path, indicated by arrows.

3Specialized machine or self-propelled mechanism for unrolling, heating, and pressing the roll roofing material onto the prepared substrate.

4Self-propelled cart or material handling equipment used for transporting rolls of roofing material or hot bitumen.

5Expansion joints, filled and sealed to accommodate thermal movement of the building structure.

6Machine or equipment for cleaning and drying the roof base, ensuring proper adhesion of subsequent layers.

7Compressor or specialized unit used in conjunction with cleaning equipment, possibly for air-blowing debris.

8Thermal insulation layer, consisting of rigid boards or panels laid over the vapor barrier.

9Leveling screed, applied over the thermal insulation to provide a smooth, sloped surface for the waterproofing layers.

10Guide rails or screed boards, used to control the thickness and slope of the cement screed.

11Freshly poured and leveled cementitious material forming the screed.

12Distribution nozzles or application wands for spraying liquid materials like primer or mastic.

13Spray nozzle used for applying liquid primer over the prepared and sealed expansion joint area.

14Bitumen pump unit, stationed at ground level or lower roof level, supplying hot bitumen or mastic.

15Distribution manifold or valve system controlling the flow of hot bitumen/mastic to the roof level.

16Main feed line or riser pipe transporting liquid bitumen/mastic from the heating unit to the roof.

17Bitumen melting kettle or mobile heating plant for preparing hot mastic/bitumen.

18Hoist or lifting mechanism (window crane or similar) for transporting materials from the ground to the roof.

19Material receiving platform or staging area at the roof edge.

20Zone for the application of the protective gravel layer, consisting of embedded gravel to protect against UV and mechanical damage.

21Zone for the application of the main rolled roofing carpet.

22Zone for priming the base surface prior to laying the waterproofing.

23Zone dedicated to the sealing and preparation of thermal expansion joints.

24Zone for cleaning and drying the structural base.

25Zone for the installation of the vapor barrier layer.

26Zone for the installation of the thermal insulation layer.

27Zone for the application of the cementitious leveling screed.

1. Шаг 1: Входной контроль рулонных материалов (проверка поверхностной плотности, целостности крошки и гибкости на брусе радиусом 10 мм).
2. Шаг 2: Подготовка клеящего состава (праймера) путем смешивания битума 70/30 с растворителем в пропорции 1:3 в специализированных смесителях закрытого типа.
3. Шаг 3: Разметка захваток на плоскости кровли с учетом направления уклона (от 2,5% до 10%) и расположения водосточных воронок.

Reinforced concrete panels serve as the load-bearing base for the roof; the joints between them must be obligatorily grouted with a cement-sand mortar with a compressive strength of not less than 10 MPa or fine-grained concrete of class C8/10 (B8.5). It is also permitted to use flat asbestos-cement or cement-bonded particle boards with a thickness of 10 mm as a prefabricated screed. To prevent warping, such boards are primed on both sides, and 100 mm wide strips are laid under the joints of adjacent sheets.

To protect the thermal insulation from the diffusion of water vapor from interior spaces, a vapor barrier is installed over the load-bearing structure. Before laying it, the concrete surface is cleaned of cement laitance, dedusted by industrial compressors, and dried. The painted vapor barrier is made of cold polymer-bitumen mastics or chlorinated rubber varnishes. The adhered vapor barrier is installed from a polyethylene film with a thickness of at least 200 µm or foil-clad materials with mandatory sealing of overlaps.

A critical parameter at this stage is the evenness of the base. Tolerances are checked with a standard three-meter straightedge: gaps should not exceed 5 mm when the straightedge is laid along the slope and 10 mm when laid across. No more than one gap with a smooth profile is allowed per meter of the straightedge length. Sharp protrusions and height differences at slab joints exceeding 5 mm are subject to mandatory grinding.

1Rolled roofing material (top layer of the roofing carpet) being unrolled and applied in overlapping strips

2Direction of movement of the roofing equipment/workers during the application of respective layers

3Mobile machine for laying and gluing the rolled roofing carpet

4Motorized buggy or cart for transporting roofing rolls to the installation zone

5Bitumen distribution nozzle or applicator attached to the supply hose for applying hot mastic

6Temperature/expansion joints filled with elastic sealant or compressible material

7Mobile air compressor or blower unit used for cleaning and drying the base surface

8Surface drying machine equipped with heating elements for preparing the substrate

9Rigid thermal insulation boards (e.g., mineral wool or foam glass) laid in a staggered pattern

10Worker manually positioning and adjusting the thermal insulation boards

11Cement-sand leveling screed applied over the thermal insulation layer to provide a rigid base for roofing

12Leveling guide or screed rail used to maintain the correct thickness and slope of the cement screed

13Intermediate pumping station or booster pump for delivering hot bitumen mastic over long distances

14Heated circulation hose system delivering hot bitumen mastic from the central station to the work zones

15Main delivery pump for hot bitumen mastic located at the central heating station

16Distribution manifold or valve controlling the flow of bitumen mastic to different hose lines

17Control panel or operator station for managing the bitumen heating and pumping system

18Central mobile bitumen melting and heating station (kettle) situated outside the main work area

19Fuel supply tank or utility connection for operating the bitumen heating station

20Auxiliary pump or compressor supporting the central heating station operations

1. Шаг 1: Инструментальная проверка качества заделки межплитных швов и нивелировка поверхности несущих конструкций.
2. Шаг 2: Очистка и обеспыливание железобетонного основания с использованием промышленных компрессорных установок.
3. Шаг 3: Нанесение окрасочной пароизоляции или наклейка рулонного пароизоляционного барьера с нахлестом не менее 100 мм.
4. Шаг 4: Установка закладных деталей, гильз для пропуска инженерных коммуникаций и монтаж чаш внутренних водосточных воронок.

Rigid board thermal insulation materials must have a compressive strength at 10% deformation of not less than 0.06 MPa and be resistant to solvents. The boards are laid in one or several layers. In multi-layer installation, the joints of the upper layer are staggered relative to the joints of the lower layer to eliminate cold bridges. Adhesion is performed using hot bitumen mastic (softening point 75-80 °C), applied in 20 cm wide strips with a spacing of 40-50 cm.

To ensure efficient drainage, the design slopes are strictly maintained. In the valleys, the slope is formed within 1-3%. Around the internal roof drain funnels, at a distance of 0.5-1.0 m, the slope is artificially increased to 5-10% to create a receiving bowl with a diameter of about 1 m and a depth of 5-10 cm. At the eaves overhangs (at a distance of 0.2-0.5 m from the edge), with minor roof slopes, the local slope is increased to a minimum of 25%.

Loose-fill insulation materials (expanded clay, perlite) are supplied by pneumatic installations and laid in layers no more than 10 cm thick along screed guide rails with thorough compaction. Monolithic thermal insulation made of lightweight concrete is laid in alternating strips 4-8 m wide, with transverse expansion joints 15-20 mm wide cut every 2-6 meters. Concreting of monolithic insulation is allowed only at outdoor air temperatures not lower than +5 °C.

1Worker in protective workwear and safety goggles, performing the installation tasks

2Long-handled spreader or trowel, used for applying and levelling the mastic/adhesive

3Bucket containing mastic, adhesive, or levelling compound

4Layer of applied mastic or adhesive, serving as the bonding agent for the floor covering

5Floor covering material (e.g., linoleum, vinyl, or carpet roll), being laid over the adhesive

6Prepared base floor or substrate (e.g., concrete screed), ready to receive the adhesive and covering

1. Шаг 1: Разметка уклонов, установка маячных реек и направляющих для формирования водоразделов и ендов.
2. Шаг 2: Нанесение горячего битума полосами на пароизоляцию и укладка первого слоя жестких минераловатных плит.
3. Шаг 3: Укладка второго слоя утеплителя со смещением швов (вразбежку) и подрезка уступов между плитами, превышающих 5 мм.
4. Шаг 4: Формирование занижений (чаш) вокруг водосточных воронок и увеличенных уклонов на карнизных свесах.

Over the board insulation or monolithic lightweight concrete, a leveling screed of cement-sand mortar 15 mm thick is applied. The compressive strength of the mortar must be at least 5 MPa (grade M50). When performing work in winter conditions, a mortar with a strength of 10 MPa (M100) using expanded clay sand and the addition of potash in an amount of 10-15% of the cement mass is used. The temperature of the mixing water in this case should be +30 °C, which allows work to be carried out at air temperatures down to -33 °C.

In the autumn-winter period, the installation of screeds 15-30 mm thick from sand asphalt concrete with a compressive strength of not less than 0.8 MPa (at a temperature of 50 °C) is permitted. Over rigid bases, the thickness is 15-20 mm, over non-rigid bases — 20-30 mm. Asphalt concrete is laid along guide rails in 2-3 m strips and compacted with manual rollers weighing 80-100 kg. It is important to note that the installation of asphalt concrete screeds is strictly prohibited over loose-fill insulation and on slopes exceeding 20-25% due to the risk of slipping under the influence of summer temperatures.

To prevent cracking in screeds, expansion-shrinkage joints up to 5 mm wide are mandatory to be cut. They divide cement-sand screeds into sections no larger than 6x6 m, and asphalt concrete screeds — no larger than 4x4 m. In decking made of prefabricated slabs, the section size is reduced to 3x3 m. The joints must strictly coincide with the end joints of the load-bearing slabs. On top of the joints, strips of roll material 150 mm wide are laid with spot adhesion only on one side of the joint.

1Main circulation pipe connecting the upper header to the heat exchange blocks

2Upper vertical header or expansion tank for the cooling medium

3Upper distribution manifold with flow control valves directing fluid into the cooling channels

4Top-level heat exchanger block or cooling radiator section

5Main return pipe routing cooled fluid from the top section back to the system

6Lower vertical header or reservoir for the cooling medium

7Mid-level heat exchanger block or cooling radiator section

8Intermediate distribution manifold routing fluid between radiator levels

9Vertical interconnecting pipe between the upper and lower headers

11Lower-mid level heat exchanger block or cooling radiator section

12Bottom-level heat exchanger block or cooling radiator section

13Bottom distribution manifold supplying fluid to the lowest radiator levels

14Main return pipe routing cooled fluid from the bottom section back to the system

15Lowest heat exchanger block or cooling radiator section

16Lower connecting pipe from the main horizontal header to the distribution manifolds

17Lower flow control valve regulating fluid input to the lower sections

18Intermediate interconnecting pipe between mid-level distribution manifolds

1. Шаг 1: Установка маячных реек и подача цементно-песчаного раствора на кровлю с помощью пневмонагнетателя.
2. Шаг 2: Укладка раствора картами (полосами) с разравниванием рейкой-правилом и уплотнением площадочными вибраторами.
3. Шаг 3: Нарезка температурно-усадочных швов шириной 5 мм с заданным шагом (6х6 м для цементной стяжки).
4. Шаг 4: Перекрытие сформированных швов полосами рубероида шириной 150 мм с односторонней точечной фиксацией.

At the junctions of the roof with vertical structures (parapets, walls, ventilation shafts), transition fillets (cants) made of cement-sand mortar are obligatory. The height of the fillet must be at least 100 mm. It is performed either at a 45-degree angle (100% slope) or as a smooth curve with a radius of 100-150 mm. This prevents the roll material from breaking when transitioning from a horizontal to a vertical plane.

Immediately after placing the fresh cement-sand screed, its surface is primed with a solution of grade 90/10 bitumen in a slow-evaporating solvent (solar oil) in a ratio of 1:2 or 1:3. The consumption of such a primer is 0.2 kg/m². Application on fresh mortar allows the primer to deeply penetrate the pores, and the resulting film protects the screed from premature moisture evaporation, substituting concrete curing. When priming asphalt concrete bases, 70/30 bitumen is used with a consumption of 0.8-1.0 kg/m².

The preparation of vertical surfaces (walls, parapets, pipes) is performed to a height of 150-350 mm from the roof level, depending on the climatic region. At this height, a 40x60 mm antiseptic wooden batten is embedded into a chase for the mechanical fixation of the roof carpet edge. The surface beneath the junction is leveled with a layer of cement-sand mortar (strength 10 MPa) 10-15 mm thick flush with the embedded batten.

1Scaffolding decking planks — horizontal wooden boards forming the main working platform surface

2Vertical support post — timber upright member transferring loads from the platform to the base or ground

1. Шаг 1: Устройство цементно-песчаных переходных бортиков (высотой от 100 мм, угол 45°) в местах примыканий к парапетам с помощью доски-шаблона.
2. Шаг 2: Монтаж деревянных антисептированных реек (40х60 мм) в штрабы вертикальных конструкций на высоте 150-350 мм.
3. Шаг 3: Нанесение праймера на свежеуложенную цементную стяжку удочкой-распылителем (расход 0,2 кг/м²).
4. Шаг 4: Технологический перерыв до полного высыхания грунтовочного слоя (определяется тестом 'на отлип', ориентировочно 24 часа).

Before the start of the roofing carpet installation, strict instrumental acceptance of the base is carried out. Compliance with design slopes from water divides to roof drain funnels is checked. The presence of counter-slopes (reverse slopes) is strictly not allowed, since even with a 1-3% slope, the slightest unevenness will lead to water stagnation. In valleys, the evenness is checked using a tightly stretched cord between the funnels — the distance from the cord to the bottom of the valley should not exceed 5 mm.

The adhesion of the roll carpet by the flameless method begins only after the primed surface has completely dried (checked 'tack-free'). The rolls are unrolled and glued using a solvent that plasticizes the lower polymer-bitumen layer of the membrane. To ensure reliable adhesion and remove air bubbles, professional equipment is used: heavy pressure rollers (force 70-150 N, strip width up to 150 mm). The roller is equipped with a balancing system that allows copying minor surface irregularities.

Eaves overhangs with free water discharge are additionally reinforced. The edge of the roll material is wrapped around the overhang, nailed to an embedded wooden board, and finished with galvanized roofing steel (drip edge). The drip edges of the steel finishing are bent away from the eave by at least 30 mm. The top layer of the roofing carpet made of a material with a protective slate dressing is glued with an offset of the longitudinal and transverse joints relative to the lower layer in accordance with the manufacturer's technological regulations.

1Vertical construction joint or expansion joint, designed to manage thermal expansion and contraction within the concrete channel structure

2Central drainage trench or slot, positioned at the lowest point of the V-shaped invert to collect and channel water flow

3Sloped concrete invert of the channel, facilitating the gravitational flow of water towards the central drainage trench

4Vertical concrete side wall of the drainage channel, retaining the adjacent soil and directing water flow within the channel

5Surrounding soil or compacted subgrade material, providing foundational support to the concrete drainage structure

1. Шаг 1: Инструментальная проверка уклонов (особенно в ендовах) и ровности основания трехметровой рейкой.
2. Шаг 2: Нанесение растворителя на нижний слой мембраны и поверхность основания для активации вяжущего.
3. Шаг 3: Раскатка рулона с одновременной прикаткой тяжелым кровельным катком (усилие 70-150 Н) для исключения воздушных линз.
4. Шаг 4: Механическая фиксация краев ковра на карнизных свесах и установка стальных оцинкованных капельников с отгибом слезника на 30 мм.